Cooling water supply system and air separation plant

Abstract

The utility model provides a cooling water supply system and air separation equipment. In the cooling water supply system, a water return pipe system is arranged to convey cooling water to the tower body from the water pool of the water cooling tower. A refrigerator and a cooler are arranged in the water return pipe system, the water return pipe system is provided with a series pipeline which enables cooling water to sequentially pass through the cooler and the refrigerator from the water tank and then reach the tower body, and a booster pump is arranged at the position, between the cooler and the refrigerator, in the series pipeline. The cooling water supply system can be beneficial for preventing the refrigerant in the refrigerator from being liquefied when the temperature of the cooling water source is low.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of air separation, and relates to an air separation device, more particularly to a cooling water supply system. BACKGROUND

[0002] Cooling water supply systems are often involved in air separation devices, for example, cooling water needs to be supplied to coolers in the air separation device, so that the coolers can cool other components. Commonly, a pre-cooling system in the air separation device needs to use a chiller to provide chilled water to an air cooling tower, and the chiller itself needs to use cooling water for cooling, which also needs to use a cooling water supply system.

[0003] It is found in practice that in winter, due to the excessively low temperature of the cooling water, the refrigerant in the chiller is easily liquefied in the upper space of the condenser and mixed with the lubricating oil in the lubricating system. This can cause poor lubrication and further lead to excessively high temperature of the compressor bearings and rotor.

[0004] Therefore, it is desirable to solve the above problems and avoid such abnormal situations. SUMMARY

[0005] The purpose of the utility model is to provide a cooling water supply system which can help to avoid liquefaction of refrigerant inside the chiller when the temperature of the cooling water source is low.

[0006] The further purpose of the utility model is to provide a cooling water supply system which can supply cooling water with a temperature that is not excessively low to the chiller at a relatively low cost.

[0007] The utility model provides a cooling water supply system. The cooling water supply system comprises a cooling tower and a return water piping system. The cooling tower has a tower body and a water pool. The return water piping system is arranged to send cooling water from the water pool to the tower body. The return water piping system has a chiller and a cooler arranged therein. The return water piping system has a series connection pipeline through which the cooling water passes from the water pool to the tower body in sequence through the cooler and the chiller. A booster pump is arranged in the series connection pipeline at a position between the cooler and the chiller.

[0008] In one embodiment, the cooling water supply system further comprises a pipeline adjusting assembly. The pipeline adjusting assembly comprises a series connection on-off valve arranged on the series connection pipeline and used to open and close the series connection pipeline.

[0009] In one embodiment, the series connection on-off valve comprises two isolation valves arranged on the series connection pipeline immediately upstream and downstream of the booster pump.

[0010] In one embodiment, the water return system has a first water return line and a second water return line for the cooling water to pass through the chiller and the cooler respectively from the water pool to the tower body, the first water return line and the second water return line are parallel to each other, the water inlet is connected to the same water inlet line leading from the water pool, the water outlet is connected to the same water outlet line leading to the tower body, and the water return pump is arranged in the water inlet line.

[0011] In one embodiment, the rated power of the booster pump is lower than that of the water return pump.

[0012] In one embodiment, the cooling water supply system further comprises a pipeline regulating assembly, and the pipeline regulating assembly comprises a first on-off valve, which is arranged in the first water return line and located upstream of the chiller.

[0013] In one embodiment, the water return system further has an additional line leading from a second downstream position downstream of the cooler in the second water return line or a water outlet leading position in the water outlet line. The additional line leads to the chiller. The outlet of the additional line is connected to a first introduction position between the chiller and the first on-off valve in the first water return line. The additional line and a first downstream pipe section of the first water return line downstream of the first introduction position both constitute a series pipeline.

[0014] In one embodiment, the additional line leads to the chiller from the water outlet leading position, so that the series pipeline is composed of the water inlet line, the second water return line, a water outlet upstream pipe section of the water outlet line upstream of the water outlet leading position, the additional line, the first downstream pipe section and the entire water outlet line in sequence through which the cooling water passes.

[0015] In one embodiment, the pipeline regulating assembly further comprises a series on-off valve for opening and closing the series pipeline. The series on-off valve is arranged in the additional line.

[0016] The utility model also provides a kind of air separation equipment. Air separation equipment includes air cooling tower, for precooling to feed air. Air separation equipment further includes aforementioned cooling water supply system. Chiller is cooled by cooling water in cooling water supply system, and then provides refrigeration water to air cooling tower.

[0017] In the above cooling water supply system, the temperature of the cooling water supplied to the chiller will rise a little because the cooling water has passed through the cooler before. Therefore, even when the temperature of the cooling water source is low, such as in winter, the temperature of the cooling water supplied to the chiller can be raised a little, so that the liquefaction of the refrigerant inside the chiller can be avoided.

[0018] Moreover, in the above cooling water supply system, by adding a booster pump between the chiller and the cooler in the series pipeline, the booster pump can be used to overcome the pressure drop at the chiller and pump the water required by the chiller when needed. If not needed, such as in summer, the ordinary setting from the pool to the tower body can be used. In this way, the energy consumption and water consumption from the pool to the tower body can be greatly reduced, and the existing components do not need to be upgraded too much. That is, the above cooling water supply system can supply cooling water with a temperature that is not too low to the chiller at a low cost. BRIEF DESCRIPTION OF DRAWINGS

[0019] The advantages and spirit of the present application can be further understood through the following detailed description and drawings.

[0020] Figure 1 is a schematic diagram of an exemplary cooling water supply system according to an embodiment.

[0021] Figure 2 is a schematic diagram of an exemplary cooling water supply system according to a comparative example. DETAILED DESCRIPTION

[0022] The specific embodiments of the present application will be described below in detail with reference to the accompanying drawings. However, the present application should be understood as not being limited to the following described embodiments, and the technical concept of the present application can be implemented in combination with other known technologies or functions, or with other technologies that are the same as those known technologies.

[0023] For example, the first feature described above or above the second feature in the specification can include an embodiment in which the first feature and the second feature are formed by direct connection, and can include an embodiment in which an additional feature is formed between the first feature and the second feature, so that the first feature and the second feature can not be directly connected. Further, when the first element is described in connection with or in combination with the second element, the description includes an embodiment in which the first element and the second element are directly connected or combined with each other, and an embodiment in which one or more other intervening elements are added to indirectly connect or combine the first element and the second element with each other.

[0024] The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well-known functions or constructions can not be described in detail for brevity and / or clarity.

[0025] As mentioned in the background, too low temperature of cooling water can cause a series of problems of the chiller and its related equipment. Therefore, the temperature of cooling water entering the chiller in winter cannot be too low.

[0026] The inventors believe that cooling water with relatively high temperature can be drawn from the cooling water return line of other coolers to the chiller, which will be described later in Figure 2 Further analysis shows that the chiller can cause additional pressure drop. Therefore, the discharge pressure of the return pump needs to be increased considering this abnormal operation, and a pump body with stronger pressure increasing capacity is selected to meet the flow of both the chiller and other coolers. This can significantly increase the investment cost such as facility procurement and the maintenance cost such as energy consumption.

[0027] Figure 1 An exemplary configuration of the cooling water supply system 10 is shown. The cooling water supply system 10 includes a cooling tower 1 and a return water piping system 2. The cooling tower 1 has a tower body 11 and a water pool 12.

[0028] It can be understood that the drawings herein are only examples and are not necessarily drawn according to the same scale, and should not be considered as limiting the actual protection scope required by the utility model. It can also be understood that in the cooling tower 1, a fan is usually arranged in the tower body 11 to cool the water entering from the middle or upper part of the tower body 11 to a lower temperature and then discharge it downward under the action of gravity. The water pool 12 is placed below the tower body 11 to receive the low-temperature water discharged from the tower body 11, and thus can output cooling water q0 to the outside.

[0029] The return water piping system 2 is arranged to send the cooling water q0 from the water pool 12 to the tower body 11. The return water piping system 2 is provided with a chiller 20 and a cooler 30. The return water piping system 2 has a series piping s0 that allows the cooling water q0 to pass through the cooler 30 and the chiller 20 in sequence from the water pool 12 to the tower body 11. A booster pump 32 is arranged in the series piping s0 at a position between the cooler 30 and the chiller 20.

[0030] The chiller is a machine that can provide chilled water. The cooler is another component that can be used to help cool a flow or component, such as a post-cooler commonly used in air separation equipment. The post-cooler is used to cool the high-temperature air usually discharged from the outlet of the compressor or booster to below 40°C.

[0031] It can be understood that "pipeline", "pipe", "pipe section" and the like used in the present specification refer to a line through which a flow passes, and do not limit the physical form of the corresponding element. For example, a "pipeline" can refer to a section of a complete pipeline. The pipeline can also be a combination of a plurality of pipelines connected in sequence, or even in a loop, and the same pipeline can also appear repeatedly to form the pipeline. The plurality of pipelines can be connected by pipe joints or other pipeline elements such as valves and the like. The space in the pipe joint or other pipeline element through which the flow passes can also be considered as part of the pipeline. For example, Figure 1 In the following, it will be mentioned that cooling water q0 passes through the water inlet pipeline 25, the second water return pipeline 22, the water outlet upstream pipe section 261, the additional pipeline 24 and the first downstream pipe section 212, and then returns to the water outlet pipeline 26, and these pipe sections in turn form a series pipeline s0. In essence, the series pipeline s0 also includes the spaces in the isolation valves 43, 44 and the water return pump 31, the booster pump 32 and the cooler 30, the refrigerator 20 and the like through which the cooling water q0 passes.

[0032] It can also be understood that when a flow is described as entering a first element and a second element in sequence or the like, it only indicates the order in which the flow enters the first element and the second element, and does not exclude the possibility that the flow passes through the second element between the first element and the second element, or the possibility that the flow passes through the second element before the first element or after the second element. For example, the cooling water q0 is essentially sent from the water tank 12 to the tower body 11 through a plurality of components.

[0033] It can be understood that the terms "first" and "second" are only used for description purposes and are not intended to limit the time sequence, quantity or importance, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features, but only to distinguish one technical feature in the present technical solution from another technical feature. Therefore, the features limited by "first" and "second" can explicitly or implicitly include one or more of the features. In the present specification, "a plurality of" means two or more (i.e. more than two), unless otherwise specifically specified. Similarly, the limiting words appearing in the present specification, such as "one", are not intended to limit the quantity, but to describe a technical feature that has not appeared in the preceding text. Similarly, unless a specific quantity quantifier modifies a noun, the present specification should be considered to include both singular and plural forms, and the present technical solution can include a single technical feature or a plurality of technical features.

[0034] Continuing to refer to Figure 1 The cooling water supply system 10 also includes a pipeline regulating assembly 4. The pipeline regulating assembly 4 includes a series switch valve 40 arranged on the series pipeline s0, for opening and closing the series pipeline s0.

[0035] The series switch valve 40 includes two isolation valves 43, 44 disposed immediately upstream and downstream of the booster pump 32 on the series line sO.

[0036] "Immediately" means that the isolation valves 43, 44 are disposed just upstream and downstream of the booster pump 32 on the series line sO, i.e., there are substantially no other elements between the isolation valves 43, 44 and the booster pump 32, generally no line junctions or branch points. Furthermore, "upstream" and "downstream" will be used herein to describe relative orientations, which are understood to be relative to the flow direction of the flow in the corresponding line.

[0037] In the above-described cooling water supply system 10, it is possible to control whether the cooling water qO reaches the tower 11 via the series line sO by opening and closing the series switch valve 40.

[0038] The return piping 2 can have a first return line 21 and a second return line 22 such that the cooling water qO reaches the tower 11 from the pool 12 via the chiller 20 and the cooler 30, respectively. The first return line 21 and the second return line 22 are parallel to each other, and the inlet ports are connected to the same inlet line 25 leading from the pool 12, and the outlet ports are connected to the same outlet line 26 leading to the tower 11. The return pump 31 is disposed in the inlet line 25. Thus, when the cooling water source temperature, i.e., the cooling water temperature at the pool 12, is too low, for example, in winter, the series line sO is used. In normal situations, for example, in summer or even in spring and autumn, the cooling water is normally returned from the first return line 21 and the second return line 22, respectively.

[0039] The cooling water supply system 10 can further include a line regulating assembly 4. The line regulating assembly 4 can include a first switch valve 41. The first switch valve 41 can be disposed in the first return line 21 and upstream of the chiller 20.

[0040] In the above-described cooling water supply system 10, it is possible to allow the cooling water qO to reach the tower 11 via the chiller 20 of the first return line 21 by opening the first switch valve 41. By closing the first switch valve 41, the cooling water qO is prohibited from reaching the tower 11 via only the chiller 20 disposed in the first return line 21.

[0041] The booster pump 32 has a lower rated power than the return pump 31. Thus, the pumping demand can be satisfied on the basis of as low cost and energy consumption as possible.

[0042] The return piping 2 can further have an additional line 24 leading from a second downstream position (similar to the position P2 in the above-described embodiment) downstream of the cooler 30 in the second return line 22 or a water outlet leading position P6 in the outlet line 26. Figure 2

[0043] ​The additional line 24 leads to the chiller 20. Figure 1 In this case, the outlet of the additional line 24 is connected to a first introduction position Pl in the first return line 21 between the chiller 20 and the first on-off valve 41. In this case, the additional line 24 and a first downstream pipe section 212 of the first return line 21 downstream of the first introduction position Pl both form part of a series circuit so. It can be understood that the first introduction position Pl can be just at the cooling water inlet of the chiller 20. The above arrangement makes it easy to isolate or open the series circuit so.

[0044] Figure 1 In this case, the additional line 24 leads to the chiller 20 from a water outlet introduction position P6, whereby the series circuit so is formed by the cooling water q0 passing through the water inlet line 25, the second return line 22, a water outlet upstream pipe section 261 of the water outlet line 26 upstream of the water outlet introduction position P6, the additional line 24, the first downstream pipe section 212 and the entire water outlet line 26 in sequence. The above arrangement can further facilitate isolation or opening of the series circuit so.

[0045] As mentioned before, the cooling water supply system 10 further comprises a circuit regulating assembly 4. The circuit regulating assembly 4 can further comprise a series on-off valve 40 for opening and closing the series circuit so. The series on-off valve 40 can be provided in the additional line 24. As mentioned before, the isolation valves 43, 44 are provided on both sides of the booster pump 32 in the additional line 24, respectively.

[0046] In the above cooling water supply system 10, for example, by closing the isolation valves 43, 44 and opening the first on-off valve 41, the cooling water q0 can be made to pass through the chiller 20 only before reaching the tower 11. For another example, by opening the isolation valves 43, 44 and closing the first on-off valve 41, the cooling water q0 can be made to pass through the cooler 30 first before passing through the chiller 20 and finally reaching the tower 11. The above operations can also be made into automatic control.

[0047] Figure 2 A cooling water supply system 10a as a comparative example is shown. In the cooling water supply system 10a, the return water piping system comprises a third line 23 parallel to both the first return line 21 and the second return line 22. The third line 23 leads from a position P2 downstream of the cooler 30 in the second return line 22 to a position Pla upstream of the chiller 20 in the first return line 21. Figure 2 In this case, the position Pla is between the first on-off valve 41 and the chiller 20. The third line 23 is provided with a valve 45, and the second return line 22 is further provided with a valve 46 downstream of the position P2. Figure 2 Figure 2In this way, the cooling water q0 can pass through the cooler 30 and the chiller 20 in sequence to reach the tower body 11 by closing the first switch valve 41 and the valve 46 and opening the valve 45. However, since the return water pump 31 needs to overcome the pressure drops of the cooler 30 and the chiller 20 and needs to supply the water quantity satisfying the cooler 30 and the chiller 20 at the same time, a pump body with large power and large flow needs to be used. Not only the procurement cost is high, but also the energy consumption is large. Moreover, when the two are not connected in series, the return water pump 31 usually operates at a low power, which not only wastes energy but also may cause damage to the pump body.

[0048] Compared with the comparative example, the above cooling water supply system 10 is arranged by pipeline layout and a booster pump 32. The booster pump 32 needs to overcome a small pressure drop and only needs to pump a small water quantity satisfying the chiller 20 from the return water pipeline 26. The procurement cost is significantly reduced, the energy consumption is significantly reduced, and the maintenance of the return water pump 31 and the booster pump 32 is particularly advantageous.

[0049] The utility model also provides a kind of air separation equipment 100.The air separation equipment 100 includes air cooling tower 60, for precooling to feed air.The air separation equipment 100 also includes cooling water supply system 10.The chiller 20 is cooled by cooling water q0 in cooling water supply system 10, and then provides refrigeration water q1 to air cooling tower 60.

[0050] It needs to be understood that refrigeration water q1 can be extracted from nitrogen water tower (not shown) of air separation equipment 100, and is frozen after being sent into chiller 20, and is not cooling water q0 used for cooling chiller 20 here.Air cooling tower 60, chiller 20, nitrogen water tower and the like can jointly constitute the precooling system of air separation equipment 100.

[0051] Unless clearly indicated to the contrary, each aspect or embodiment defined herein can be combined with any other aspect or embodiment or aspects or embodiments. In particular, any feature indicated as being preferred or advantageous can be combined with any other feature or features indicated as being preferred or advantageous.

[0052] The preferred embodiments of the utility model described in the specification are only the preferred embodiments of the utility model, and the above embodiments are only used to illustrate the technical scheme of the utility model and are not limited to the utility model. Any technical scheme obtained by logical analysis, reasoning or limited experiment according to the concept of the utility model should be within the scope of the utility model.

Claims

1. A cooling water supply system comprising a cooling tower having a tower body and a water pool, and a return water piping system arranged to send cooling water from the water pool to the tower body, the return water piping system being provided with a chiller and a cooler, characterized in that, The return water piping system has a series piping through which the cooling water reaches the tower body from the water pool in sequence through the cooler and the chiller, and a booster pump is arranged at a position between the cooler and the chiller in the series piping.

2. The cooling water supply system according to claim 1, wherein The cooling water supply system further comprises a piping regulation assembly, which comprises a series switch valve arranged on the series piping for opening and closing the series piping.

3. The cooling water supply system according to claim 2, wherein The series switch valve comprises two isolation valves arranged on the series piping immediately upstream and downstream of the booster pump.

4. The cooling water supply system according to claim 1, wherein The return water piping system has a first return water pipeline and a second return water pipeline through which the cooling water reaches the tower body from the water pool in sequence through the chiller and the cooler respectively, the first return water pipeline and the second return water pipeline are connected in parallel with each other, the water inlet of each pipeline is connected to the same water inlet pipeline leading from the water pool, and the water outlet of each pipeline is connected to the same water outlet pipeline leading to the tower body, and a return water pump is arranged in the water inlet pipeline.

5. The cooling water supply system according to claim 4, wherein The rated power of the booster pump is lower than that of the return water pump.

6. The cooling water supply system according to claim 4, wherein The cooling water supply system further comprises a piping regulation assembly, which comprises a first switch valve arranged on the first return water pipeline and located upstream of the chiller.

7. The cooling water supply system according to claim 6, wherein The return water piping system further has an additional pipeline leading from a second downstream position downstream of the cooler in the second return water pipeline or a water outlet leading position in the water outlet pipeline, and the additional pipeline leads to the chiller; The outlet of the additional pipeline is connected to a first introduction position between the chiller and the first switch valve in the first return water pipeline, and the additional pipeline and a first downstream pipeline section of the first return water pipeline downstream of the first introduction position both constitute a part of the series piping.

8. The cooling water supply system according to claim 7, wherein The additional pipeline leads to the chiller from the water outlet leading position, whereby the series piping through which the cooling water passes in sequence comprises the water inlet pipeline, the second return water pipeline, a water outlet upstream pipeline section of the water outlet pipeline upstream of the water outlet leading position, the additional pipeline, the first downstream pipeline section, and the entire water outlet pipeline.

9. The cooling water supply system according to claim 7, wherein The piping regulation assembly further comprises a series switch valve for opening and closing the series piping, and the series switch valve is arranged on the additional pipeline.

10. An air separation plant comprising an air cooling column for precooling a feed air, characterized by, The air separation plant further comprises the cooling water supply system according to any one of claims 1 to 9, and the chiller is cooled by the cooling water in the cooling water supply system to provide chilled water to the air cooling tower.

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